Chemical properties

Ra-223 is usually in divalent state.

Nuclear properties

Ra-223 decays with by ɑ decay with a half-life of 11.43(5) days. Its' decay chain involving Rn-219 (T_1/2 = 4 s), Po-215 (T_1/2 = 1.8 ms), Pb-211 (T_1/2 = 36 min), Bi-211 (T_1/2 = 2.2 min) and Tl-207 (T_1/2 = 4.8 min) leads to stable Pb-207. Including its short-lived decay chain, the cumulative ɑ emission is 400% per Ra-223 decay.

Ra-223 emits X-rays from 81 to 98 keV (49.6%) and γ-rays, notably 269 keV (13.3%), its daughter Rn-219 emits γ-rays at 271 keV (10.8%) and Bi-211 emits γ-rays at 351 keV (13%). These are the principal photon emissions of the decay chain that enable SPECT-imaging , .

Production

Ra-223 is produced at JRC Karlsruhe by separation from an Ac-227/Th-227 generator.

Distribution

Radiochemical separations are performed at the production facility JRC Karlsruhe (JRC, Karlsruhe, International). Activity will be shipped from there to the users in dry form.

Examples of use

• The main application of Ra-223 is as free Ra²⁺ ions, that act, analogously to Ca²⁺, as bone seekers. Administered as Ra-223 chloride under the product name Xofigo it is used for targeted therapy of bone metastases of metastatic prostate cancer .
• Stable chelation of Ra²⁺ with the chelator macropa has been reported .
• Encapsulation of Ra-223 in liposomes or radiolabeled nanoparticles , is being investigated.
• Radiolabeled nanomicelles are being investigated for enhanced effect on bone metastases or combined alpha and beta therapy respectively .